The present invention relates generally to building structures and, more specifically, to studs used primarily in constructing the walls of buildings.
Wood frame construction is a very common type of building construction technology used today. In the continual quest to reduce the cost of construction and to increase the productivity of the construction labor force, attention is given to reducing the cost of material, reducing the labor required for construction, and increasing the quality of the material used.
One nearly ubiquitous structural element used in wood construction is a piece of lumber called a stud. Studs are the vertical, load-bearing pieces of wood in the interior or exterior walls of a building to which sheathing or panel material is attached to form the wall structures. In addition to their use in wall construction, studs are also used in other parts of the framing process. There is a need to provide a reliable, low-cost supply of high-quality wooden studs for the construction industry.
The traditional stud is made in one piece and cut from tall trees, into 1xc2xd inch by 3xc2xd inch cross-sections (the standard 2xc3x974), or 1xc2xd inch by 5xc2xd inch cross-sections (the standard 2xc3x976), and milled into various lengthsxe2x80x94most typically 8 or 9 feet. Such studs are often subject to warping, both bending and twisting.
Among the many factors which contribute to the cost and quality of wooden studs are the following: (1) the cost of the raw material used, affected by the amount and quality of timber available and the demand for timber; (2) the cost of manufacture of the studs; (3) the cost of transportation, which, among other things, is dependent on the weight of the studs; (4) the resistance to warpage of the studs, which reduces waste and increases the quality of the resulting structures; and (5) ease of use of the studs, affected by weight and by the extent of warpage. Thus, the need for a reliable, low-cost supply of high-quality wooden studs can be translated into a need for straight, stable, lightweight studs made from a source of inexpensive raw material.
One source of inexpensive raw material used in the construction industry is oriented strand board (OSB), a dimensionally-stable engineered wood sheet product which utilizes the fiber available from xe2x80x9cwastexe2x80x9d trees which are too small to produce traditional solid-wood products such as studs. The raw material for OSB itself, therefore, is inexpensive, and the manufacturing process is highly automated, making OSB an excellent, cost-effective source of raw material for fabricated lumber.
OSB has been used in the past as part of fabricated structural members for applications such as trusses, joists, rafters, and girders, i.e., in applications in which it is necessary for a horizontal structural member to carry vertical loads across the horizontal span of the structural member. Such beams, typically in I-beam or box-beam configurations, were structures to which engineered sheet materials could be applied because of the fact that I-beam and box-beam cross-sections are efficient in withstanding the tensile and compressive loads present in such applications, not to mention the fact that timber for long-span structural members is often not readily available.
However, the concept of engineered structures and in particular hollow box structures has not been widely accepted with respect to studs, i.e., 2xc3x974 and 2xc3x976 structures for use as studs in supporting interior and exterior walls. There are several reasons for this. First, it tends to be counterintuitive to make wooden studs hollow since studs are relatively slender. Second, since studs are designed to receive and to secure fasteners such as nails, it is thought that a hollow stud would not secure the appropriate fasteners as readily as solid wood. Third, studs are sized for placement in vertical, upright positions where they carry mainly compressive forces. Thus, box-shaped designs have not typically been associated with wooden studs.
In the past, there have been a number of efforts directed to the manufacture of engineered wooden beams, primarily for horizontal beam applications, with very little effort of practical consequence being applied with respect to the manufacture of studs intended primarily to take compressive loads. In fact, essentially no engineered wooden studs, whether or not made primarily of OSB, are available in normal market channels. Furthermore, the configuration of fabricated beam structures and other structures that may be seen in prior art documents are quite complex, and thus would typically be relatively expensive to manufacture.
There has been a need for a simple, low-cost, stable compressive-load-bearing wooden stud which can be easily manufactured and easily used.
Accordingly, it is a principal object of the invention to provide a fabricated wooden stud made primarily of OSB, thereby using wood sources not able to be used for solid timber studs.
It is another object of the invention to provide an improved stud which can be produced at a minimum cost.
Another object of this invention is to provide an improved wooden stud having high structural strength without using solid timber.
Another object of this invention is to provide an improved stud that is not subject to the warping that is often typical of traditional construction lumber.
Another object of this invention is to provide a stud that has lower weight, thereby lowering transportation costs and facilitating use on construction sites.
Another object of this invention is to provide a stud having improved insulating properties.
Yet another object of this invention is to provide a fabricated stud which has the ability to receive framing nails and other fasteners used in wooden building construction.
These and other objects of the invention will be apparent from the following descriptions and from the drawings.
The instant invention is a fabricated wooden stud which overcomes the above-noted problems and shortcomings and satisfies the objects of the invention. In describing the invention, certain terminology is used which is defined at the end of this summary section.
The fabricated wooden stud of this invention includes: (1) a pair of fully-aligned face-members of OSB spaced from one another and each having first and second ends and first and second elongate edges; (2) first and second fully-aligned edge-members of OSB spaced from one another, the first and second edge-members being adhesively affixed between the face-members along the first edges and second edges thereof, respectively; and (3) a pair of end-members adhesively affixed between the face-members at the ends thereof.
In certain embodiments of the invention, the OSB planes of the face-members and the edge-members are substantially parallel. In another embodiment of the invention, the end-members are OSB, such that the entire stud is made of OSB. In a preferred embodiment of the invention, the OSB planes of the face-members, the edge-members and the end-members are substantially parallel. Manufacturing studs with OSB members the OSB planes of which are parallel greatly simplifies the manufacturing process while producing studs having substantial compressive strength.
In a particularly preferred embodiment of the invention, each of the face-members of the stud has a width equal to the width of the stud. It is also highly preferred that each of the edge-members of the stud has an elongate outer surface, the edge-members being positioned such that the outer surfaces of the first and second edge-members are substantially coplanar with the first edges and second edges, respectively, of the face-members. Another preferred characteristic of the inventive fabricated wooden stud involves the end-members having end surfaces and the end surfaces being substantially flush with the first and second ends of the stud.
In a preferred embodiment of the invention, the stud further includes at least one core-member adhesively affixed between the face-members and dividing the void which is formed by the spaced face-members and the spaced edge-members. Each core-member preferably extends from the first edge-member to the second edge-member.
In certain preferred embodiments of the invention, the end-members and the core-members are OSB, such that the entire stud is made of OSB, with OSB planes of the face-members, the edge-members, the end-members and the core-member(s) most preferably being substantially parallel.
Many of the highly preferred features are most preferably combined in a stud of this invention. That is, such stud would include all of the following characteristics: (a) the end-members and the core-members being OSB such that the entire stud is made of OSB; (b) the OSB planes of the face-members, the edge-members, the end-members and the core-member(s) are substantially parallel; (c) each of the face-members has a length equal to the length of the stud; (d) each of the face-members has a width equal to the width of the stud; (e) each of the edge-members has an elongate outer surface, the edge-members being positioned such that the outer surfaces of the first and second edge-members are substantially coplanar with the first edges and second edges, respectively, of the face-members; and (f) the end-members have end surfaces and the end surfaces are substantially flush with the first and second ends.
Additional preferred features in the inventive stud include broken corners and wiring pass-throughs. These features and their advantages are discussed below. Still another feature in certain embodiments is the inclusion of insulation material in the void space formed by the spaced face-members and the spaced edge-members.
In addition to many benefits of the invention which are seen by the fact that the invention overcomes certain shortcomings of the prior art, it should be recognized that there are benefits of creating a hollow structure in a stud. These include: (1) less raw material used (both OSB and adhesive); (2) reduced transportation costs; (3) less weight for the builders to carry during construction; and (4) improved R-value (insulating capability) from the dead-air space (or other insulating material which can be added during stud fabrication), thereby enhancing the thermal performance of the resulting walls.
In order to minimize, the cost of a fabricated stud, not only is it desirable to use an inexpensive raw material (OSB), it is desirable that the structure be made using a simple and highly-efficient manufacturing process. A description of a highly preferred method for manufacturing the stud of this invention is included below in the section below entitled xe2x80x9cDetailed Description of Preferred Embodiments.xe2x80x9d Such manufacturing method is the subject of a concurrently filed patent application Ser. No. 10/142,3002 of the same inventor, entitled xe2x80x9cMethod for Manufacturing Fabricated QSB Studs.xe2x80x9d
The intended meanings of various terms used in this document are set forth in the paragraphs which follow:
The term xe2x80x9cface-memberxe2x80x9d as used herein refers to each of the two wider elongate pieces which, in preferred embodiments of this invention, form all of the wide sides of the stud. In similar fashion, the term xe2x80x9cedge-memberxe2x80x9d as used herein refers to each of the two narrower pieces which, in preferred embodiments of this invention, form part of the narrow sides of the stud.
The term xe2x80x9cfully-alignedxe2x80x9d is used herein with respect to the two face-members or with respect to the two edge-members. The term describes two members as being sized and oriented with respect to each other in certain ways, namely: (1) the two members have substantially equal dimensions of length, width, and thickness; (2) the length directions of the two members are substantially parallel; and (3) perpendicular projections of the two members onto a plane that is perpendicular to either the thickness or width directions of the members (but not both) are fully overlapping.
The term xe2x80x9cend-memberxe2x80x9d as used herein refers to the two pieces each of which occupies the space inside the stud at an end thereof, such space being formed between the two face-members and the two edge-members.
The term xe2x80x9ccore-memberxe2x80x9d as used herein refers to each piece which is similar to an end-member but which occupies a space inside the stud at a selected location away from the ends of the stud, such spaces being formed by the two face-members and the two edge-members.
The term xe2x80x9cOSB planexe2x80x9d as used herein with respect to a particular OSB member, refers to the plane of the top surface of the sheet of OSB from which the particular member has been cut. For example, if several sheets of OSB material are layered one on top of another, their OSB planes are parallel regardless of the width and length directions of the OSB sheets from which they have been cut.
The term xe2x80x9cface-sheetxe2x80x9d as used herein with respect to a method of manufacture, refers to each of the top and bottom OSB layers of the stud assembly.
The term xe2x80x9cedge-stripxe2x80x9d as used herein with respect to a method of manufacture, refers to each of the plurality of elongate OSB pieces which are part of the stud assembly and which, when the stud assembly is cut into a plurality of studs, form the edge-members of the studs.
The term xe2x80x9cinner sheetxe2x80x9d as used herein with respect to a method of manufacture, refers to the sheets of OSB from which edge-strips, end-members, and core-members are cut.
The term xe2x80x9cstud assemblyxe2x80x9d as used herein with respect to a method of manufacture, refers to the three-layer sandwich which includes first and second face-sheets with a plurality of edge-strips, end-members, and core-members arranged in accordance with a plan accommodating the stud configuration and the subsequent cutting of the sandwich into a plurality of studs. (See FIG. 3, referred to below.)
The term xe2x80x9cassembly basexe2x80x9d as used herein refers to a preferably horizontal work surface on which the face-sheets and the various members to be sandwiched therebetween are laid up during the stud fabrication process.
The words xe2x80x9cthe entire stud is made of OSBxe2x80x9d should be understood to allow the use of adhesive to bond the various parts of the fabricated stud together and also to include the optional use of various coatings on the studs, such as a water-repellant coating over the edges of the OSB material.
The term xe2x80x9cbroken cornersxe2x80x9d as used herein with respect to a stud refers to the outer corners along the length of the stud as having been trimmed to have a small radius or slightly beveled character in order to eliminate sharp corners.
The term xe2x80x9cwiring pass-throughsxe2x80x9d as used herein refers to holes through the smallest dimension of the stud to allow electrical wiring to be installed easily in walls constructed with such fabricated wooden studs. Wiring pass-throughs in a series of studs forming a wall allow rapid wiring on the job site. The term is used herein to refer both to holes in individual members of the stud (during manufacturing) as well as to holes through the finished stud.